slither-disable-next-line does not always work on lines

I'm excited about the addition of `slither-disable-next-line`, and have been testing it from master.

It took me a little while to get it working, because the "line" that the detectors work off might be the function as a whole.

For example, suppose I wanted to disable the warning, in the following contract. This doesn't work, but is the intuitive way:

```
contract Foo {
function bar(address payable z) external returns(uint256) {
// slither-disable-next-line suicidal
selfdestruct(address(z)); // error here
return 1;
}
}

```

This works:

```
contract Foo {
// slither-disable-next-line suicidal
function bar(address payable z) external returns(uint256) {
selfdestruct(address(z));
return 1;
}
}
```

It looks like this is because the detector for `suicidal` works on functions, not lines.

(https://github.com/crytic/slither/blob/081a0717efbf983c567602d982a09780f7d74920/slither/detectors/functions/suicidal.py)

Perhaps the name `slither-disable-next-line` should be changed to something that matches the actual behavior?